The development and trial of a drastically new method is proposed for a computer-based abstract representation of long nucleotide sequences. Instead of the customary series of letters the sequnece of nucleotides would be described by a three-dimensional space curve composed of a linear assembly of minute vectors joined in a head-to-tail fashion. The four nucleotide building blocks A, T (or U), G and C would each be represented by a small unit vector pointing in a characteristic direction. Computer programs would be assembled in order to (1) convert nucleotide-sequence information from the letter system to the coordinates of the space curves, (2) display the curve on terminals, and (3) facilitate the three-dimensional visualization of space curves. The advantages of the new representation include the compactness and ease of global survey of neucleotide-sequence information. These factors are of paramount importance when handling very long nucleotide sequences which have been appearing in the literature in steadily increasing numbers due to important discoveries in DNA and RNA sequencing methods. The completion of potentiometric titration experiments on the synthetic polynucleotides poly (dG) and poly (dC) which were started during the previous grant period is also proposed.